Mari Carmen Torres-Moreno, Ph.D., from the Universitat Autònoma de Barcelona in Spain, and colleagues conducted a systematic literature review to identify randomized, double-blind, and placebo-controlled trials evaluating the effect of medicinal cannabinoids by oral or oromucosal route of administration on the symptoms of spasticity, pain, or bladder dysfunction in adult patients with MS.

Based on 17 included trials (3,161 patients), the researchers found that cannabinoids were associated with significant efficacy for spasticity, pain, and bladder dysfunction compared with placebo. Although they are considered safe, there were more total adverse events for cannabinoids. There was no significant difference in serious adverse events.

“Cannabinoids appear to be safe regarding serious adverse events, but their clinical benefit may be limited,” the authors write.